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Speed limitation in wireless transmissions

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• Signal used in wireless transmissions

  • Wireless transmission:

    Always use electro-magnetic waves Note: light is also a form of electro-magnetic wave !!!

    Example: radio wave

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• The spectrum of Electro-Magnetic waves

  • Electro-magentic waves goes by many different names, such as:

    Radio wave (this is what ordinary people would think of...) Light !! Micro-wave (the kind of electro-magnetic waves used to cook) X-ray And so on....

    The difference between the electro-magnetic waves above is:

    Their frequency....

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  • The frequencies of electro-magnetic waves spans a very wide range:

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• Transmission data at higher (data) rate
  • Fact:

    Higher data rate transmissions must use a high frequency electro-magnetic wave signal

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  • Consequence:

    To achieve very high data rate, we would have to use X-ray or gamma-ray !!! These rays are harmful to biological entities !!!!

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• Breaking news....
  • Cell phone and brain cancer:

    Be careful with your cell phones: Cellphone radiation can cause cancer: click here (Cellphone operates at frequencies that is very close to micro-wave --- the kind of waves used to cook food....